[Rupture of a thoracic aortic aneurysm into the right pleural cavity].

Rupture of an aneurysm of the descending thoracic aorta into the right pleural cavity is an uncommon event and its prognosis is rapidly fatal. Its diagnosis is difficult and it may remain unrecognized. We report the case of a 66-year-old patient with a haemorrhagic shock associated with a spontaneous right haemothorax. A ruptured aneurysm of the descending thoracic aorta was diagnosed during the surgical procedure.